RU2147705C1 - Pipe line air inlet and outlet valve - Google Patents

Abstract

FIELD: surface water lines. SUBSTANCE: valve has body with seat having straight-way hole and shut-off member. Body is fitted in pipe line and is provided with diaphragm. Area of diaphragm exceeds flow area of seat. Shut-off member is provided with rod connected with diaphragm. Body is divided into three parts by means of diaphragm and seat. Upper and center parts are communicated with atmosphere and cavity of pipe line through holes made in body. Body is provided with passage coaxial relative to straight- way hole in seat. Lower part of body is communicated with atmosphere by means of passage; it is also communicated with center part through straight-way hole of seat. Upper part of body is provided with cover into which spindle is screwed through motion nut for manually opening the valve. EFFECT: enhanced reliability; avoidance of freezing of valve. 1 dwg

Description

 The invention relates to pipe fittings, mainly for overhead pipelines.

 A device is known, described in the book "Buildings and Structures in the Far North" edited by Velli Yu.Ya., Leningrad - Moscow, 1963, Fig. IV-VII, p. 415. The device is installed on the overhead gasket pipe for air inlet and outlet. It is located in the pipe, which is installed on top of the pipe. Water filling the pipeline displaces air through openings made in the device body. When the water approaches, the float located inside the housing floats, rises and closes the bore of the shutter. In the closed position, the valve is pressed against the seat by the force determined by the law of Archimedes and the water pressure in the pipeline. When the pipeline is free of water, the float lowers, opening holes in the housing for air inlet. The device does not freeze if the thermal conduit is normal.

 When cooling the conduit, for example due to insufficient heating of the water or due to the stoppage of the movement of water, the device may freeze in the winter. Due to the large heat transfer surface of the shutter and its remoteness from the water flow, the device freezes before ice appears on the walls of the pipeline.

 Another disadvantage of the device is the deterioration of the operational properties of the float. Over time, the material of the float ages, its porosity decreases, and as a result, the gate density decreases. The work of the float is sensitive to distortions and to metal corrosion.

 The objective of the invention is to increase the reliability of the design and water supply, protection of the valve from freezing, as well as automatic and reliable protection of the pipeline from destruction by atmospheric pressure.

 The problem is solved in that in the valve for intake and exhaust of air from the pipeline in the body there is a saddle with a through hole and a shut-off element is installed, and the device body is placed in the pipeline and equipped with a diaphragm installed in it, the area of which is larger than the area of the saddle through section, and the shut-off the body is equipped with a rod connected to the diaphragm, and by means of the diaphragm and the seat the housing is divided into three parts, the upper and middle of which are communicated with openings in the housing, respectively, with the atmosphere a ferrule and a pipe cavity, while in the housing there is a channel, coaxial to the passage of the seat, through which the lower part of the body is connected to the atmosphere, communicated with the middle part through the passage of the seat, and a cover is installed on the top of the body, into which the manual spindle is screwed through the running nut valve opening.

 The proposed device eliminates the noted disadvantages. It does not freeze when the conduit stops. Studies have shown that such devices remain operational during glaciation of the pipeline to half its cross-sectional area. The ability to allow glaciation of the pipeline extends a safe shutdown (usually forced in emergency cases) for several days, which significantly increases the reliability of water supply. In the proposed device there is no float. It is very simple in terms of design, its details are equal in pipeline durability. Significant superiority of the aperture area over the area of the orifice provides a high shutter density. The output (it is the input) channel of the device is made vertically downward from the shutter, which eliminates the convective movement of air in the body space, protects the valve from freezing.

 The proposed device is shown in the drawing, section.

 In the above-ground pipeline 1, the housing of the device 2 is installed, which is divided by diaphragm 3 and saddle 4 into three parts that are different in design and technological purpose. The valve 5 is connected to an elastic diaphragm. The upper part of the casing is closed by a cover 6 and communicates with the atmosphere with openings 7. The middle part communicates with the space of the pipeline by openings 8, and the bore of the shutter - with the lower part of the casing and then with the atmosphere. The spindle 9 has a threaded spindle nut 10. A valve is fixed to the stem 11. The glass 12, the pipe 13 press the diaphragm with a threaded ring 14 to the cover 15. The boundary of the ice layer in the pipeline is shown at 16. The pipe insulation is not shown conventionally.

 The device operates as follows. When the pipeline is emptied, when a water outlet opens at a lower point in the overhead or duct gas duct, or in case of emergency water leakage, for example, due to damage to the joint in the pipeline, pressure below atmospheric arises. In this case, the diaphragm is affected by atmospheric pressure from above and water pressure below below atmospheric. As a result, the diaphragm goes down and opens the valve interacting with it. Thus, the passage for air from the atmosphere to the pipeline will open. In this case, a balance of forces is established in the system. The loss of air pressure to overcome local resistance in the valve and in the openings of the housing is determined by the difference in pressure from the atmosphere and water in the pipeline. The greater the pressure difference, the higher the pressure and the greater the speed that air enters the pipeline. At the same time, feedback is observed: the flow of air into the pipeline reduces the pressure difference across the diaphragm and leads to shutter closure.

где R - полное термическое сопротивление трубопровода, м^oC/Вт;
V_в - объем воды, отнесенный к 1 м трубы;
γ_в - плотность воды, кг/м³;
C_в - удельная теплоемкость воды, Вт•ч/кг^oC;
t_в - температура воды в момент остановки движения, ^oC;
t₀ - температура таяния льда, ^oC;
t_с - температура окружающей среды, ^oC.The valve response to the appearance of vacuum in the pipeline is instantaneous. In all modes, the device automatically and reliably protects the pipeline from destruction by atmospheric pressure. In contrast to the emptying of the water conduit, which can occur accidentally as a result of a rupture of the joint of the pipeline or damage to the fittings, the start-up of the water conduit is carried out in an organized manner by the operation workers. Before filling the conduit by rotating the handwheel, the spindle 9 is lowered, opening the shutter. The air from the water duct passes through the openings 8, the bore of the shutter, the lower part of the housing and enters the atmosphere. For water conduits equipped with the proposed device, the permissible stop time of the movement of water in the water conduit is determined by the cooling time of the water to the freezing temperature T ₁ and the formation time of the ice ring T ₂ . The cooling period of water to 0 ^o C in hours is determined by the formula

where R is the total thermal resistance of the pipeline, m ^o C / W;
V _in - the volume of water referred to 1 m of the pipe;
γ _in - the density of water, kg / m ³ ;
C _in - specific heat of water, W • h / kg ^o C;
t _in - water temperature at the moment of stopping the movement, ^o C;
t ₀ - ice melting temperature, ^o C;
t _with - ambient temperature, ^o C.

где γ_л - плотность льда, кг/см³;
r₃ - скрытая теплота ледообразования, Вт•ч/кг;

- отношение площади поперечного сечения ледяного кольца F_л к площади сечения трубопровода при отсутствии льда F.The time of formation of the ice layer in the pipeline

where γ _l is the density of ice, kg / cm ³ ;
r ₃ - latent heat of ice formation, W • h / kg;

- the ratio of the cross-sectional area of the ice ring F _l to the cross-sectional area of the pipeline in the absence of ice F.

 The maximum permissible value of the pipeline glaciation at this level of valve technology depends on the possibility of putting the icy pipeline into operation after eliminating the emergency and the absence of ice in the input (output) channels of water supply devices.

 Studies have shown that the permissible value of the pipeline glaciation can be taken m = 0.5. With such glaciation, a certain reserve remains in case of deviation of the actual heat loss from the calculated one. Half the cross section of the pipe is also sufficient to resume the movement of fluid in the pipeline.

 Due to the heat generated by the water when it turns into ice, the allowable stop time of the surface laying water conduit increases by 10-20 times depending on the initial temperature of the liquid, the diameter of the pipe and the degree of glaciation.

Claims (1)

 Valve for air inlet and outlet from the pipeline, in the body of which a saddle with a through hole is made and a shut-off element is installed, characterized in that the body is placed in the pipeline and is equipped with a diaphragm installed in it, the area of which is larger than the saddle passage section area, and the shut-off element is equipped with a stem connected to the diaphragm, and by means of the diaphragm and the seat, the housing is divided into three parts, the upper and middle of which are communicated with openings in the housing, respectively, with the atmosphere and the pipe cavity and, wherein the housing is formed coaxial passage opening saddle channel through which communicates with the atmosphere the lower housing portion, communicated with the middle portion through the opening of the seat, and on the upper part of the housing mounted cover, which through a lead nut screwed spindle manual valve opening.